The initial copper with large grain sizes of 60-100 μm was processed by six passes asymmetrical accumulative rolling-bond （AARB） and annealing, the ultra-fine-grained （UFG） copper with grain size of 200 nm was ob...The initial copper with large grain sizes of 60-100 μm was processed by six passes asymmetrical accumulative rolling-bond （AARB） and annealing, the ultra-fine-grained （UFG） copper with grain size of 200 nm was obtained, and the microstructures and properties were studied. The results show that there are large sub-structures and also texture component C for the UFG copper obtained by six passes AARB, possessing high strength and microhardness in company with poor elongation and conductivity. Thereafter, the UFG copper was annealed at 220 °C for 35 min, in which the sub-structures disappear, the grain boundaries are composed of big angle grain boundaries, and the textures are composed of a variety of texture components and parts of twins. Compared with the UFG copper obtained by six passes AARB, the tensile strength and yield strength for the UFG copper obtained by six passes AARB and annealing at 220 °C for 35 min are decreased slightly, the elongation and conductivity are improved obviously.展开更多
The myeloperoxidase (MPO) is an important microbicidal protein present at high concentration in the primary granule of mature granulocyte and its expression is regulated in both myeloidcell-lineage and premyelocytic-s...The myeloperoxidase (MPO) is an important microbicidal protein present at high concentration in the primary granule of mature granulocyte and its expression is regulated in both myeloidcell-lineage and premyelocytic-stagespecific manners. A better understanding of the underlying control mechanisms should provide insights into the temporal and co-ordinate regulation of the gene expression during granulopoiesis. We have identified its promoter by mapping the start(s) of transcription using various molecular approaches together with demonstrating the promoter function of the relevant DNA segment in a transient transfection reporter assay. Besides the major start of transcription mapped at G residue, 11 nucleotide upstream of the 3’ end of exon 0, the usage of that is specific to the MPO expressing cell lines, we have shown that irrespective of the MPO-expression status of the hematopoietic cells, transcription occurs broadly within a two kb region upstream of the 5’ proximity of the gene, and is largely terminated in nitron 2. These data support a model of the pre myelocytic-stage-specific MPO expression, the control of which is operated at initiation as well as elongation levels of transcription.展开更多
基金Project (50804018) supported by the National Natural Science Foundation of ChinaProject (ZDS2010015C) supported by Key Lab of Advanced Materials in Rare and Precious and Non-ferrous Metals, Ministry of Education, KMUST, ChinaProject (2010DH025) supported by Yunnan Province Construction Plans of Scientific and Technological Conditions, China
文摘The initial copper with large grain sizes of 60-100 μm was processed by six passes asymmetrical accumulative rolling-bond （AARB） and annealing, the ultra-fine-grained （UFG） copper with grain size of 200 nm was obtained, and the microstructures and properties were studied. The results show that there are large sub-structures and also texture component C for the UFG copper obtained by six passes AARB, possessing high strength and microhardness in company with poor elongation and conductivity. Thereafter, the UFG copper was annealed at 220 °C for 35 min, in which the sub-structures disappear, the grain boundaries are composed of big angle grain boundaries, and the textures are composed of a variety of texture components and parts of twins. Compared with the UFG copper obtained by six passes AARB, the tensile strength and yield strength for the UFG copper obtained by six passes AARB and annealing at 220 °C for 35 min are decreased slightly, the elongation and conductivity are improved obviously.
文摘The myeloperoxidase (MPO) is an important microbicidal protein present at high concentration in the primary granule of mature granulocyte and its expression is regulated in both myeloidcell-lineage and premyelocytic-stagespecific manners. A better understanding of the underlying control mechanisms should provide insights into the temporal and co-ordinate regulation of the gene expression during granulopoiesis. We have identified its promoter by mapping the start(s) of transcription using various molecular approaches together with demonstrating the promoter function of the relevant DNA segment in a transient transfection reporter assay. Besides the major start of transcription mapped at G residue, 11 nucleotide upstream of the 3’ end of exon 0, the usage of that is specific to the MPO expressing cell lines, we have shown that irrespective of the MPO-expression status of the hematopoietic cells, transcription occurs broadly within a two kb region upstream of the 5’ proximity of the gene, and is largely terminated in nitron 2. These data support a model of the pre myelocytic-stage-specific MPO expression, the control of which is operated at initiation as well as elongation levels of transcription.
